Mysterious 9th Planet
How can you find a mystery planet?
Explore the resources below to learn how scientists use math to predict where a planet will be found and technology to see new planets. As you explore, look for the meaning of these words:
- Kuiper Belt (objects)
- Axis of Rotation
- Dwarf Planet
- Orbit
- TNOs - trans-Neptunian objects
- SDOs - scattered disk objects
Planet 9: New Theories About the HIDDEN Giant Planet
Watch the video to explore what scientists are learning about the mysterious Planet 9.
- What made scientists think there might be a hidden large 9th planet?
- How would a 9th planet solve this phenomenon?
- If there is a planet that is 10X the size of Earth, why haven't we seen it before?
- What is an alternate hypothesis that might account for the movements of objects in the outer solar system?
Is the elusive "Planet Nine" tilting the solar system?
Click the picture below to read the article. As you read, look for the answers to the discussion questions.
- Even though scientists have not seen Planet 9, why do they think it might be there?
- Explain how the size of Planet 9 would relate to the ability to tilt the rest of the solar system out of alignment.
- How has the tilt of the solar system changed over time?
TED Talk: The Search for Planet Nine
This TED Talk features Dr. Masao Sako from the Univesity of Pennsylvania explaining how new scientific technology is being used to search for Planet 9.
- Why have the first 6 planets been known for a very long time?
- How were Uranus & Neptune discovered?
- How do you find an object in our solar system?
- What new discovery has Dr. Sako's team found from the data?
The Mystery of Finding Neptune
Neptune is too far away from Earth for us to see with our eyes. For many years no one had any idea Neptune was a planet in our solar system. It was not until scientists started noticing that Uranus moved differently than predicted by mathematical formulas that scientists started looking for explanations and objects further out in the solar system. In 1845 a scientist use math to predict where a new "Mystery Planet" would be found. The next year astronomers used his math calculations to find Neptune -- it was found within 1 degree of it's predicted placement! Read through this story by clicking the picture below to learn how scientists used math to find a new planet.
- What were some of the reasons scientists hypothesized to explain why Uranus's orbit was different than predicted?
- It was a big coincidence that the scientists who used math to predict Neptune's orbit did so in 1845. What would have happened if the scientists had done this math 20 years in the future or past?
- With our current technology, could Neptune have been discovered without using math formula predictions? If so, explain how.